Clarify the definition of "inside conditions"

[TyMick]

I just got tripped up violating the first rule of Hooks in a situation like this:

export function ListGrid({ settings, groupId, itemId }) {
  const { Grid, Placeholder } = useLazyGrid();
  if (!Grid) {
    return <Placeholder />;
  }

  const [text, setText] = useState('');
  ...

I'd only been thinking in visual terms about whether useState was being called at the top level. Sure, it wasn't inside a conditional statement, but coming after that early exit meant it was still only called under certain conditions, which, now I know, still counts.

eslint-plugin-react-hooks does catch this situation, for the record, but the situation confused me so much I thought it might be nice to add a clarification to this page that "don't call Hooks inside conditions" doesn't just mean "inside conditional statements". useState here doesn't feel like it's "inside" anything.

Might be a better way and/or place to explain this idea, but this is a start, at least.

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[rickhanlonii]

Thanks!